如图,已知多面体
中,
,
平面
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/77d0ea08-1a33-4893-9fa9-28dc3bd458f0.png?resizew=146)
(Ⅰ)证明:
平面
;
(Ⅱ)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea1e3a43d0fa18f6c0888ba804d5b329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0facf189b2a3153beb7b9e077d3b1146.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d5ba108d7d2d4807f2c74a22e536fe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e12bfde565540f059dd27ea47dfaa7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/77d0ea08-1a33-4893-9fa9-28dc3bd458f0.png?resizew=146)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45fbffb9e2c7fa7c5006cde8da0cabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(Ⅱ)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
更新时间:2019-02-04 10:13:33
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在四面体
中,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40bdf4b769034a94e4a488148d5bf25.png)
,二面角
是直二面角,
为
的中点,点
为线段
上一点,且
.
![](https://img.xkw.com/dksih/QBM/2021/2/25/2665851876081664/2671194726326272/STEM/cccdaa438e8b4fd489ccecca8c441778.png?resizew=189)
(1)求证:
平面
;
(2)求平面
与平面
所成锐二面角的平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40bdf4b769034a94e4a488148d5bf25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5336fe7dd901d5555ba705f78020fc98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f1854ba6cc92481d7a616bd2788a47e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58ac6979adfa3b30c6067a9fdfd49f08.png)
![](https://img.xkw.com/dksih/QBM/2021/2/25/2665851876081664/2671194726326272/STEM/cccdaa438e8b4fd489ccecca8c441778.png?resizew=189)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828fcf6ed16b5dae1b572d471f5ed7a7.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828fcf6ed16b5dae1b572d471f5ed7a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,在四棱锥
中,
底面
,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/11/3c3ce8da-9469-4b9a-87d6-f9aed8c0933a.png?resizew=162)
(1)求证:
平面
;
(2)试在棱PB上确定一点
,使截面
把该几何体分成的两部分
与
的体积比为
;
(3)H是PB中点,求二面角
大小的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9060f03b9ee41d70d135b1e1a8902ce9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bdb3995265a321989202ff01001013d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcc532cfe64300cb3da9e04a307c957a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79dd389c1ca8b13d3e3b191c990c2426.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/11/3c3ce8da-9469-4b9a-87d6-f9aed8c0933a.png?resizew=162)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)试在棱PB上确定一点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b50d70e1882717eb8a14b510ae82b832.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f8fe593425f016a9d257f559e2d6b03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbe103f073845122c66f22dcb14b711f.png)
(3)H是PB中点,求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff119dc1e8ed3c824e466c4217e3bbcc.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在直三棱柱
中,
,
,
分别为
和
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/2/784ab481-ce59-43f1-8506-17c6dc6c21a5.png?resizew=151)
(1)求证:
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14d355b4c58b4e883b9e65cc6da8622e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0023280949eda97787964f0a9d41ed2e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/2/784ab481-ce59-43f1-8506-17c6dc6c21a5.png?resizew=151)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0451505215f3b34ca3bacf948251f70.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,已知平面
平面
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/24/f306f155-d132-4829-a689-2f1a5e872d0c.png?resizew=180)
(1)连接
,求证:
;
(2)求
与平面
所成角的大小;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/780d3f5f4c4419913c1232b7aae03ade.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df7eb8d02ae228f12bed947432daabe2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bca76d0d2614f113bcd4c9e134b95123.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/24/f306f155-d132-4829-a689-2f1a5e872d0c.png?resizew=180)
(1)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4739afd7311501e948aa4e1e5c1cb17.png)
您最近一年使用:0次